1. Field of the Invention
The invention is directed to protective glasses for fitting on a protective helmet and a helmet with protective glasses. More particularly, the invention is directed to an elongate, at least longitudinally curved lens panel for protecting the eyes, having two side pieces, each of which can have, or have, an inner end articulated on the helmet and a helmet with such protective glasses.
2. Discussion of the Related Art
Protective glasses of the type mentioned herein are known from U.S. Pat. No. 6,892,393 B1. The known protective glasses, instead of having a frame with two side pieces and two lenses fitted into the frame, have a continuous lens panel, which replaces the frame and the two lenses. On the side adjacent to the head, the lens panel has two angled portions, which are essentially parallel to one another, at its outer ends. Each of the two side pieces have their outer or distal end articulated in a latchable manner on said two angled portions. Each of the two side pieces have their inner or proximal end articulated on a plug. The plugs can be introduced into slots formed in the lower periphery of a protective helmet. If eye protection is not required, the lens panel is tilted upward, about its points of articulation on the side pieces, out of a protective position, located in front of the eyes of a person wearing the helmet, into a stowage position. During this tilting operation, the two side pieces change neither in position nor in length. The outer ends of the two side pieces are provided with annular bearings, in which two hubs formed on the lens panel are mounted such that they can be rotated about their articulation axes. The arrangement here is such that the two articulation axes are aligned with one another. Each annular bearing is provided with axial grooves in the 12 o'clock, 9 o'clock and 10.30 positions, so that the lens panel is held in position when it has been pivoted or tilted into a lower position (0°), an intermediate position (75°) or an all-the-way-up position (90°). Latching here in each case is soft latching, that is to say latching which can easily be disengaged by virtue of the lens panel being pivoted or tilted by hand. Provision is therefore also made, as an alternative to the aforementioned latching of the lens panel on the two side pieces, for a friction fit, which allows stepless angle adjustment of the lens panel. In the stowage position, the lens panel, when viewed from the side, has approximately only up to a third of its extent penetrating into the space enclosed by the protective helmet, while the rest of the lens panel remains visible beneath the protective helmet. In this stowage position, the person wearing the protective helmet can easily see in the forward direction beneath the lens panel. If the protective helmet is used for forestry work, it is conceivable for branches to catch on the protective glasses when the lens panel is in this stowage position, and this carries the risk of the protective helmet being torn off the wearer's head.
In the case of another known pair of protective glasses, known from EP 1 853 129 B1, this risk is somewhat smaller because there is a change in the length of the side pieces of the glasses when the lens panel is moved into, and out of, the stowage position. This appears to make it possible to shift the stowage position further into the helmet. For this purpose, the two arms of each side piece are connected to one another by an intermediate articulation. Shortening of the length of the side pieces as the lens panel is being moved upward has the advantage that the lens panel, in its stowage position, is fully enclosed by the helmet. However, in the stowage position of the lens panel, the two side pieces project beyond the lower periphery of the helmet and can thus be caught by branches. Although the lens panel can be moved into the stowage position using one hand, both hands are required for moving the lens panel back into the protective position. This is problematic both in industry and for forestry work, because the person wearing the helmet, following a period during which the lens panel is located in the stowage position, is usually already holding the tool in one hand, and therefore he only has the other hand free for moving the lens panel back into the protective position. During this movement back, it is necessary not just for the two arms of each side piece to be pivoted at its intermediate articulation; in addition, it is also necessary for the lens panel to be pivoted about its articulation axes on the side pieces, in order to reset a certain tilting position of the lens panel in relation to the glasses arms. However, this is not readily achievable using one hand. The stowage of the lens panel or of the protective glasses per se does not usually pose any problems, because the person wearing the protective helmet has sufficient time here, because he is not in the process of working. However, when he begins to work, for example to saw, again, he has the saw in one hand and uses the other hand to try and move the lens panel as quickly as possible into the protective position, since it is important to re-establish protection quickly. This is barely achievable, however, using one hand.